I don't think we can dismiss the bank accounts so quickly. In his testimony, Mulroney showed himself to be a hair-splitter. He had previously said that he had no bank accounts outside of Canada; in his testimony this week, needing to weasel out of charges they he crossed the border with illegal amounts of cash, he said that while he had no accounts, he had a safety deposit box in a bank in New York.
Why not apply the same logic to his Swiss testimony? He may have a safety deposit box in Switzerland. More likely, GCI or some other helpful group has a bank account that it uses to siphon illicit cash to Mulroney. It's not Mulroney's account, but it's there for Mulroney.
We shouldn't accept Mulroney's word on these issues because they simply don't ring true. Caught taking money when he wasn't legally able to, he claimed the only explanation that would partly exonerate him: he was doing international lobbying. Asked to provide details, the only information he provided was the vague answer that he talked to two men who are, alas, dead and gone. He provided absolutely no corroborating evidence, and we have to conclude that he provided none because there is none: the entire story is a lie.
Al Capone shielded his illegal activities so successfully that the only thing the government could get him on was tax evasion. We should continue to try to get to the bottom of Mulroney's shennanigans, but if we can't, we should bring him in on tax evasion charges and throw the book at him.